The Enge split-pole spectrograph is a magnetic device originally
designed by Harold Enge for Scanditronix Corporation. The description of the
instrument can be found in Ref. [1].

The device was created primarily to study nuclear reactions with
light-ion projectiles but was adapted at ORNL to study heavy ion reactions
as well. It can be operated in two basic modes: high vacuum or
gas-filled. The high vacuum mode is typically
to study high resolution particle (mainly proton and alpha) spectroscopy
of the kind discussed in Ref. [2] and the gas-filled mode is adequate to
measure heavy ion reaction recoils (see Ref. [3]) for cases where
the recoil products are distributed over many charge states.
A computer program (FATRUMP
developed by J. Ford, S. T. Thorton, and J. Gomez del Campo)
is available in order to set the important parameters needed for a given
reaction. The program predicts the magnetic field needed to focus the
reaction products and the location of the focal plane for optimum resolution.
The maximum magnetic field is 16 KG for a current of about 450 A. The
focal plane length is about one meter corresponding to a maximum radius of
curvature of 90 cm and to about 60 cm for a minimum. Inside the camera box
(never used with photographic plates) there are several mechanisms that move
a support from which the detector is hanged. This allows the placement
of the focal plane at the predicted position given by the code
FATRUMP.

Presently the focal plane is equipped with a
position sensitive avalanche detector
(xy position sensitive), followed by a total energy plastic
scintillator. A description of this system is given in Ref. [3].
We have used all kinds of focal plane detectors ranging from
position sensitive solid state detectors (PSD) to proportional
counters of the Borkowski-Kopp type. These detectors still exist
and can be used upon request.